Refresh media comment action payload

[subzeroid]

Summary

• refresh media_comment write payload to include current action context fields used by feed write actions
• add regression coverage for comment creation payload and reply handling
• fix live account helper URL building so workflow account pools are not accidentally pinned to one stale account
• fix the live comment test to upload its own media, call media_comment, read the created comment back, and cleanup via comment_bulk_delete / media_delete
• add a dedicated comment target to the live account workflow
• document that comment creation remains a write action subject to Instagram spam/trust checks

Refs #2097.

Tests

• .venv/bin/python -m pytest tests/regression/test_comments.py -q
• .venv/bin/python -m pytest tests/regression/test_helpers.py tests/regression/test_comments.py -q
• .venv/bin/python -m pytest tests/regression/test_comments.py tests/regression/test_media.py::MediaActionPayloadRegressionTestCase tests/regression/test_hardening.py::HardeningRegressionTestCase::test_send_private_request_promotes_404_not_found_body_to_challenge -q
• .venv/bin/python -m pytest -sv tests/regression/test_extractors.py::ExtractorsRegressionTestCase tests/regression/test_public.py::PublicRegressionTestCase tests/regression/test_public.py::PrivateGraphQLRequestRegressionTestCase tests/regression/test_direct.py::DirectMixinRegressionTestCase tests/regression/test_challenge.py::ChallengeRegressionTestCase tests/regression/test_comments.py::CommentRepliesRegressionTestCase tests/regression/test_current_app_profile.py::CurrentAppProfileRegressionTestCase tests/regression/test_auth_story.py::AuthAndStoryRegressionTestCase tests/regression/test_download.py::DownloadRegressionTestCase tests/regression/test_notes.py::NoteMixinRegressionTestCase tests/regression/test_location.py::LocationMixinRegressionTestCase tests/regression/test_media.py::UserMediasGraphQLRegressionTestCase tests/regression/test_user.py::UserMixinRegressionTestCase tests/regression/test_timeline.py::TimelineRegressionTestCase tests/regression/test_story_configure.py::StoryConfigureRegressionTestCase tests/regression/test_video_metadata.py::VideoMetadataRegressionTestCase tests/regression/test_upload.py::UploadRegressionTestCase
• .venv/bin/python -m ruff check instagrapi tests
• .venv/bin/python -m ruff format --check instagrapi tests
• .venv/bin/python -m mkdocs build --strict
• .venv/bin/python -m build

Live verification

• Local tests/live/test_comments.py::ClientCommentExtendTestCase::test_media_comment did not reach the comment endpoint because account setup failed on proxy tunnel 302 Found during launcher/sync/.
• GitHub live account workflow comment target passed: https://github.com/subzeroid/instagrapi/actions/runs/26124367512